Putting my 30" wheels back on and decided to ask what you fellers torque your large wheel nuts up to? (the one that holds the wheel on the spindle)
The rear 15/16 nut to about 70 ft pounds.
The front finger tight, then locked with a small wrench.
The rear axle nuts you tighten with a 48" breaker bar until they are tight. Cotter key them and drive for a half hour. Then remove the cotter pins and tighten them again as tight as they can go and still get a cotter pin in. Install cotter pins and hub caps. There is no torque spec that is correct. No one at Ford or at any Ford dealership ever had a torque wrench.
The front wheel nuts tighten using the tool from the tool pouch, or a 6" crescent wrench. Tighten only until snug, then install a cotter pin. Fill the hubcap entirely with grease, and install the hubcap.
Can any one show me where Ford used a 48" pry bar? The axle is a holding taper and if you have good axles and hubs it should only take a normal wrench abd pull tight. A drill press has a double arbor. One end goes into the spindle and the other end goes into the chuck. It is a holding taper only. No key,s or nuts. Just the taper. And we drill holes for years and they never come out. Its a poor " mechanic" that will pull his guts out to fix something. Scott
I agree with Royce that during the production of the Model T Ford they did not assemble the chassis and other parts using torque specifications or torque wrenches. Nor did they use safety glass in the windshields. Just because they did not use something back then does not mean it might not be helpful or even whimsical for us to use or consider using today.
The mechanic working on the Fords back then had a good “feel” for how tight (or loose in the case of front wheel bearings) a nut or bolt etc. should normally be. A long time ago in a full service station far …far away …. I had gotten fairly good at knowing how hard to pull on something and when to take a different approach. In one case we were going to change the thermostat in an older V-8 engine car. We needed to drain the coolant level down a bit so we tried to open the drain on the bottom of the radiator. It was really stuck. I suggested that we loosen the lower radiator hose rather than turn any harder on the drain fitting. But I was just the teenager who was there for weekend help. So the other guy put a little more torque on the radiator drain and broke it out from the radiator (it never did turn it just twisted out the female threaded part that had been soldered to the radiator.) Now days I’m no longer turning wrenches very often. So rather than guess when I have 50-55 ft lbs on the Model T head bolts, I use a torque wrench – even though Ford did not. The same for the rear axle nut. It is a 5/8 x 18 TPI nut. That is the same nut that is used on the 1928-1931 Model A Ford rear axle and the 1932-1948 Ford rear axles. And as mentioned in a previous posting Bratton’s Antique Auto Parts in their 2001 parts catalog recommends 100ft-lbs of torque (dry) for the Model A rear axle nut. And you can check the various torque tables for similar numbers (for SAE 2 bolts/nuts one table has 110 for that combination while the same table shows the SAE 5 at 180ft-lbs (all dry numbers). And for a good article on the nuts and bolts I would recommend “How to Restore Your Model A Vol 3” pages 95 to 97.
Concerning a 4 ft wrench to tighten the rear axle nut. I sort-of remember seeing a really large wrench in one of the photos on the assembly line – but when I just looked, I did not locate it. I did locate where in the Service Bulletins and the same information is repeated in the Ford Service Manual (T-1) on page 24 & 25 that Ford used the No. 5-Z-248, wrench that was 20 inches long on the car rear axle nut. The Ford Service Manual is available on line at: http://mtfci2002.readyhosting.com/manuals/Model_T_Service_Manual/mtsm.html and I pasted in the words and photos related to tightening the rear wheel nut below:
74 Install rear wheel
(a) Before installing wheel, examine hub key (See “A” Fig. 70) in axle shaft, and hub felt
“B” in wheel to make sure they are in good condition.
(b) Slip wheel over end of axle shaft, making sure that key “A” in shaft enters keyway “C” in
hub of wheel.
(c) Run down and securely tighten axle shaft nut, locking the nut with a cotter key.
(d) Tightening rear wheels on axle shafts is an operation requiring special attention. If the
axle shaft nut is not draw down tightly, the wheel hub will clash against the key on the
shaft, ultimately resulting in breakage of the shaft either from crystallization or because
of the chipping off of small pieces of steel, which work around the shaft, eventually
cutting both shaft and hub. Owing to the importance of this operation, hexigon head box
shaped wrenches, having handles 20” and 25” long, should be used in tightening axle
shaft nuts on both car and truck (See “A” Fig. 71). Wrenches of this description can be
obtained from nearest Ford Branch. The wrench used on the car is listed under symbol
No. 5-Z-248, while the one used on the truck is listed under symbol No. 5-Z-591. When
wheels are installed while car is on assembly line, a bar, details of which are shown in
Fig. 72, can be used to prevent the wheels from turning. The forked end of bar is placed
over drive shaft tube as shown at “B” Fig. 71 with the flat end of bar resting on spoke of
Fig 71 is shown below:
Fig 72 is shown below:
I personally believe the wrench was long so the person on the assembly line etc. could tighten it without having to strain a lot. I.e. anyone could tighten a couple of them. But for an 8 hour shift you would want a tool that allowed you to do it easier rather than pulling with all your might. Just my thoughts on that one – it isn’t documented.
Note, having stripped a rear axle nut out using about an 18 inch breaker bar once, I would not recommend putting everything you have into a 48 inch bar/wrench on the rear axle nut. But if you do, please report back the approximate number of pounds of force you applied (i.e. if you weigh 150 lbs and stand on the bar at the 4 ft mark on the bar that is parallel to the earth’s surface, you would be applying approximately 550 ft-lbs of torque to the nut. That is from memory also – if I have the number wrong – please put the correct numbers in there. Also please don’t jump on the bar – instantaneous loads are hard to figure out. And please let us know if you had dry or lubricated threads and if the nut stripped or held.
Note just for comparison purposes, below is a photo showing the wrench used to tighten the hubcaps on the 10,000,000 Model T as it went down the line. I don’t think they applied as much torque as they could have but rather what would hold the cap in place. [Of course the photo may have just been staged – if anyone has additional information on what wrench was used on the assembly line in 1924 to tightened the hub caps with – please let us know.]
So similar to “what type of oil to use” or “should you use a distributor” etc. there are varied opinions on the usefulness of a torque wrench and torque value as well. But I will use one as I don’t do enough mechanical work to be able to do it accurately by feel. I’m sure Royce and many others don’t need to use a torque wrench – they know what is about right. And if most of us turned more wrenches more often we would not need to use torque wrenches as much either.
Hap l9l5 cut off
On a lighter side, from a similar thread at: http://www.mtfca.com/discus/messages/411944/469939.html Ken Kopsky posted his recommended torque wrench scale shown below:
And Dan Treace printed it out and will hopefully report back if it needs any additional adjustments to the scale etc. His prototype test equipment is shown below.
Hap l9l5 cut off
With Ken Kopsky's permission, I am going to label my torque wrench appropriately in order to keep myself out of trouble. Thanks Hap!
I've been given to understand that the rear wheel nuts need to be "really, really tight," which, of course, is anything
but specific. -I won't recommend what I do, but will share just for the sake of giggles: -I stand with one foot on the
running-board and the other on the big, adjustable wrench on the wheel nut. -Going just by feel, I transfer a good
deal of my not inconsiderable weight from the running-board to the wrench.
Yeah, it's one step above having a gorilla jump up and down on the wrench, but so far, the wheel has stayed on and
I haven't stripped anything. -The human torque-wrench gets recalibrated every Thanksgiving.
I would feel a lot safer tightening the nuts with a torque wrench to 70 ft pounds than using a 48 in. breaker bar to tighten them til tight. Tight enough for Grandpa Weezer is different than for his son Fat Albert. It would be nice to have a reference that the average guy could use.
FWIW I tighten them to 90 foot pounds and then look to see how much more is needed to tighten till you can insert the cotter pin. If less than 1/2 a flat tighten and key. If more than a 1/2 a flat remove the nut and add a shim washer under the nut and repeat till you get it to less than 1/2 needed to cotter. I haven't stripped any axle threads in 35 years using this method.
Bob C., I would not trust an adjustable(Crescent) wrench for that job myself. They are notorious for slipping and deforming/rounding off the flats on a nut, especially when tightening something as small as an axle nut that tight. Even using an open end is questionable. Also, if you use it backwards, it can break the adjustable jaw. It's much better to use a box end wrench or socket, in my opinion. Just a heads up. Dave
I asked this very same question a week or two back because i was concerned about stripping, or even breaking off the tip of the axle if over-tightened. I guess that since Henry's boys tightened everything "by feel" it seems we have to follow and do the same. I will follow with the opinion that 75-100 ft.lbs is probably more than reasonable especially if you check it after driving it a bit. Just my 2 cents from a newbie
every car i have ever owned that had tapered axles, had loose hubs when i bought it. royce is rite, tighten them , and tighten them again, and maybe even again
Clayton, you and I must buy our cars from the same folks! HAHA.
I don't recall the "T" number for it, but I have the Txxxx wrench sold to dealers for tightening the rear axle nut. It is a really heavy-duty open end wrench with a slightly offset handle (to clear the rim) and is about 20 inches long.
I would last about 2 hours on the assembly line using that thing and trying to get the nut tight enough each time.
BTW, the wrench is obviously old, and matches the picture for it, but it appears to be completely unused. As long as it is in my posession, it will remain unused, in lieu of a good quality socket and breaker bar.
Your analogy of the drill press spindle & chuck is really only valid for a drill press, and even then, not always true.
For transmitting torque while drilling a hole, (where the force also tends to push the chuck onto the spindle), the taper drive does fine. However, if you ever put a sanding drum in a drill press spindle and applied a side load to the taper joint, you may then run the risk of breaking the taper free. For this very reason there are chucks made with a screw-on collar to prevent it from coming loose in "side load" applications. Since a Model T wheel is very much side loaded at times, a well tightened nut is essential.
All that being said, I agree that a 48" pry bar is excessive, but only if it's used to its greatest advantage. Royce does seem to suggest that it should be. I would go for something less.
What Jerry say's is true because mills use a different taper than a Morse Taper.I think a 30" breaker bar should be enough? Bud.
I think there is good chance your open end wrench was used for a different process on the assembly line. Note the illustration below of the 20 inch wrench used on the car and listed under the symbol No. 5-Z-248: (Ref 1925 Price List of parts as well as page 600 of Bruce's book "Model T Ford".
I believe that also matches the wrench in the Ford Service book. Note I did not find out what wrench was used prior to the Dec 1925 Price List of Parts book. Perhaps someone els may have that information?
Hap l9l5 cut off
years ago, one of the clubs published a very complete guide to tools with illustrations...the wrench that I have is a 3-Z-xxxx and was identified as the rear axle wrench. I looked for it last night and darned if I can locate it to publish the actual number. The wrench you posted is of the type that I'd actually use, given the chance...
Thanks for looking. I'll try to check and see if I can find another number listed for rear axle nut wrench. I’m sure they had one prior to 1925 (although they didn’t need it for the straight rear axles). When I did a quick search the other day -- that was the only rear axle wrench that showed up. But if the name/number is in a photo or illustration my search engine does not find it. And perhaps this may be another one of those where they once thought this was the correct answer and it may or may not need to be updated?
Don't worry about searching for the wrench -- but if you come across it please let us know the numbers and letters as well as the size of the opening.
Or if anyone else knows what the number on the open end rear axle nut wrench that Scott is talking about -- please let us know. That should allow us to find out more information about it.
Hap l9l5 cut off
Hap - Thanks for your contributions to this online community. Your posts are always informative, helpful and respectful.
Thank you, I appreciate the encouragement. And thanks to everyone who helps make this site so enjoyable and informative. Sometimes I don't need another "fact" just a good laugh -- like Ken's new decal for the torque wrench settings. And at other times some one posts a question or photo etc. that leads to previously "lost information" being better documented. Like the story of the stone soup, we all have more as each of us shares what we have. And unlike some things, when you give information away / share it - you not only still have it, you often gain even more.
Keep those cards and posting coming!
Hap l9l5 cut off
You can use any length breaker bar. I carry a 12" Crescent wrench under the back seat on tours. It can develop enough torque if I stand on it.
Warning, some of the reproduction axle nuts are not made too well. I've seen people install the new nut and then strip out the axle a few times. Re using that original sort of rusty nut with good threads is always a better answer.
A problem with tightening with a certain length handle is that each man has a different strength and weight. The only consistent way to tighten the nuts is with a torque wrench. Same goes for head and other bolts and nuts.
the wrench I was speaking of is a 3-Z-375. I finally found it last night (sitting exactly where it belonged, of course!) It does not look to have been shortened, and is about 13" long...not the sort of wrench I'd want to be doing production work with, however it matches the picture and description of the axle nut tool shown on tool list from Ford. It is slightly bowed and allows your knuckles to easily clear the spokes when in use.
I particularly enjoy collecting original tools, as the style and length of them gives a good indication as to the expected tightness of a given fastener...for example, the front perch nut wrench is a real beast relative to the axle nut wrench, though they're both completely interchangeable.
Thank you so much for taking the time to find the wrench, take the photos and posting them. First the really easy part – it looks like it is a Ford script wrench….I did some searching but I could not find any Model T Ford wrench marked 3-Z-375. I thought well maybe the first number was really a 5 but no 5-Z-375 either. But looking for 3Z-675 did turn up an “Open end wrench (Rear Axle).” Would you please double check and see if it could be 3Z-675 instead of 3Z-375?
Bruce (RIP) has it listed on page 600 of his book under 5Z-206 which was the same wrench. In the Price list of Parts for Oct 1917; Dec 1917; Dec 1918; and Apr 1919 it is listed as part number 3Z-675 and also factory number 3Z-675. Then starting with the Dec 1920 and going through the Jay 1924 Price List the part number changed to 5Z-206 as well as the factory number. And for the May 1925 Price List of Parts it had an “R” added to end of the Part Number and Factory Number which I believe indicates it was for replacement and not current production. And that 5Z-248 replaced it and it appeared in the Dec 1925 Price List of Parts.
Does anyone have a 5Z-206 for comparison?
Also at the bottom of the posting at: http://www.mtfca.com/discus/messages/411944/451827.html?1402620251 James Golden shared, “I recently saw a tool with two different 3Z numbers cast in and on opposite sides.
One side had 3Z629 and the other side had 3Z675.
I don't know what it was for or why there were 2 numbers.
There do seem to be many tool variations.”
+++++++++++++++++++++++++++ End of re-post of James’ comments +++++
In this case the 3Z629 it is listed as the Open End Wrench (rear spring perch nut). So as is often the case I have more questions than when I started…..
Again thank you for finding and posting the photos of your wrench and if you think it is a 3Z-675 that fits nicely with what is recorded. And if not – more to research at a later date.
I still find it hard to believe Ford would recommend an open end wrench when the box end or socket would normally be less likely to slip. Of course that was one very rugged open end wrench.
Hap l9l5 cut off
Hap, looking at his picture, it indeed looks like 3z-675.
Yep...I fat fingered it...3Z-675...
Scott and Chad,
Thanks for the confirmation about the number.
Hap l9l5 cut off
I used to torque mine to 75 lbs. I checked and found the torque had relaxed a bit from driving. After reading these posts and others like them, I decided to retorque higher. Moving to the next cotter pin slot brought me to 150 lbs which was more than I expected. At that level, it felt like it could not go any higher. No doubt it will relax down to probably around 130 after driving and should stay tight forever.